Australian dinosaur discoveries
Very few dinosaur fossils have been found in Australia, yet Australia has many rocks of the right age to contain dinosaurs. Why have so few been found?
Australia is mostly a low, flat land, with few mountains, deep river valleys, canyons or other geological features that expose rocks that may contain dinosaur fossils. Most of Australia's vast plains are very ancient, and any exposed fossils in these areas are likely to have been destroyed by weathering.
Australia’s dinosaurs state by state
The vast majority of Australia’s dinosaur bones come from north-central Queensland, found in Early Cretaceous rocks formed about 140 million years ago (mya). But even though this is the richest Australian dinosaur region, finds are still rare, and fewer than 10 skeletons are known, some of them rather incomplete. These include the iguanodont Muttaburrasaurus and the ankylosaur Minmi. Both are somewhat atypical of their groups and suggest that Australian dinosaurs, when better known, may turn out to be rather different from their contemporaries elsewhere in the world. Queensland has also produced two very incomplete sauropod skeletons: Rhoetosaurus brownei, from the Middle Jurassic (170 mya), and Austrosaurus mckillopi from the earliest Late Cretaceous (90 mya).
New South Wales and South Australia
The opal fields of Lightning Ridge in New South Wales have produced virtually all of Australia’s opalised dinosaur bones. These are from marine sediments of early Cretaceous age. In South Australia, the Andamooka opal field has produced a single bone of a small theropod called Kakuru. Much more common than dinosaurs in the Australian opal fields are the bones of marine reptiles, particularly plesiosaurs. Whereas the opalised dinosaur remains are all single bones, a few nearly complete opalised skeletons of marine reptiles have been found at Andamooka and Coober Pedy in South Australia and White Cliffs in New South Wales.
The quintessential Australian Dinosaur, an opalised femur or thigh bone of a hypsilophodontid dinosaur from Lightning Ridge
Photographer: John Broomfield / Source: Museum Victoria
In Victoria, a large number of isolated bones (but only two partial skeletons, both hypsilophodontids) have been found in a few small coastal outcrops. For a decade, bones were mostly found at a site called Dinosaur Cove near Cape Otway. At this locality it was necessary to blast tunnels underground to reach the fossils. The site was considered exhausted at the end of 1994. Work is now underway at another site 300 km to the east of Dinosaur Cove called Flat Rocks, near Inverloch. Flat Rocks is about 10 million years older than Dinosaur Cove. The most common dinosaurs found at these locations are hypsilophodontids, but theropods, ornithomimiosaurs, protoceratopsians, and ankylosaurs have also been found.
From the vast area of Western Australia, only six dinosaur bones have been discovered in three different marine formations ranging in age from the Middle Jurassic (170 mya) to the Late Cretaceous (90 mya). One of the oldest is a partial bone of a theropod named Ozraptor. Systematic searching for fossil marine reptiles continues in Western Australia, and may eventually yield an occasional dinosaur bone or even a skeleton.
Given the scarcity of fossil bones of dinosaurs in Australia, it is fortunate that dinosaur trackways or footprints are relatively common and greatly add to our knowledge of Early Cretaceous and Middle Jurassic dinosaurs in Australia. Palaeontologists at the University of Queensland are going to great lengths to develop techniques to collect and analyse trackway information. Much of this collecting involves getting access to trackways on the roofs of coal mines, which can only be reached using elaborate scaffolding.
Map of Australia showing locations at which dinosaur fossils have been found
Source: The Dinosaur Society
Norman, D. 1985. The Illustrated Encyclopaedia of Dinosaurs. Salamander Books Limited, London.
M. J., Norell, M., McKenna, M. C. and Clark, J. 2004. Fossils of the Flaming Cliffs. Pp. 56-63 in Scientific American Special Edition: Dinosaurs and other monsters Vickers-Rich, P. Monaghan, J. M., Baird, R. F. and Rich, T. H. 1991. Vertebrate Palaeontology of Australasia. Pioneer Design Studio, Novacek.
Vickers-Rich, P. and Rich, T. H. 1993. Australia’s polar dinosaurs. Scientific American July 1993: 50–55.
Vickers-Rich, P. and Rich, T. 2004. Dinosaurs of the Antarctic. Pp. 40-47 in Scientific American Special Edition: Dinosaurs and other monsters.
Vickers-Rich, P., Rich, T. H., Rich, L. S. and Rich, T. 1997. Australian Dinosaurs. Kangaroo Press, Sydney.